Season of Light begins in 1788, in the heady days just before the French revolution, when Paris is fizzing with new ideas about liberty and equality. Asa Ardleigh, the impressionable 19-year-old daughter of a country squire, has traveled to the city with her older sister, Philippa, and Philippa's new husband. In Paris, they are introduced to the literary salon of Madame de Genlis. It is in this salon that Asa meets, and falls in love with, a dashing intellectual and idealist, Didier Paulin. Their affair is curtailed when Asa is forced to return to England, but they continue to write as the storm clouds gather over France and war with England seems imminent. Meanwhile back at home, no one knows of Asa's liaison. Asa's middle sister, Georgina, has met Harry Shackleford, the most eligible man in London that season, and to whom the Ardleigh estate is entailed. After the death of their mother, the Ardleigh girls' father began to drink heavily and now the estate is nearly bankrupt. In Shackleford, Georgina sees not only a fortuitous marriage for her sister, but also the solution to their financial woes. However Asa's accomplishments need some polishing. Georgina therefore employs Madame de Rusigneux, a French Marquise. Asa soon discovers there is more to this woman than meets the eye...